From: Bart Van Assche <bvanassche@xxxxxxx> [ Upstream commit 7252a3603015f1fd04363956f4b72a537c9f9c42 ] Instead of tracking which tags are in use in the ufs_hba.lrb_in_use bitmask, rely on the block layer tag allocation mechanism. This patch removes the following busy-waiting loop if ufshcd_issue_devman_upiu_cmd() and the block layer accidentally allocate the same tag for a SCSI request: * ufshcd_queuecommand() returns SCSI_MLQUEUE_HOST_BUSY. * The SCSI core requeues the SCSI command. Cc: Can Guo <cang@xxxxxxxxxxxxxx> Cc: Stanley Chu <stanley.chu@xxxxxxxxxxxx> Cc: Avri Altman <avri.altman@xxxxxxx> Cc: Tomas Winkler <tomas.winkler@xxxxxxxxx> Link: https://lore.kernel.org/r/20191209181309.196233-2-bvanassche@xxxxxxx Tested-by: Bean Huo <beanhuo@xxxxxxxxxx> Reviewed-by: Avri Altman <avri.altman@xxxxxxx> Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx> Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/scsi/ufs/ufshcd.c | 121 +++++++++++++++----------------------- drivers/scsi/ufs/ufshcd.h | 6 +- 2 files changed, 50 insertions(+), 77 deletions(-) diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index 289edf70ccb9..e84617172968 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -496,8 +496,8 @@ static void ufshcd_print_tmrs(struct ufs_hba *hba, unsigned long bitmap) static void ufshcd_print_host_state(struct ufs_hba *hba) { dev_err(hba->dev, "UFS Host state=%d\n", hba->ufshcd_state); - dev_err(hba->dev, "lrb in use=0x%lx, outstanding reqs=0x%lx tasks=0x%lx\n", - hba->lrb_in_use, hba->outstanding_reqs, hba->outstanding_tasks); + dev_err(hba->dev, "outstanding reqs=0x%lx tasks=0x%lx\n", + hba->outstanding_reqs, hba->outstanding_tasks); dev_err(hba->dev, "saved_err=0x%x, saved_uic_err=0x%x\n", hba->saved_err, hba->saved_uic_err); dev_err(hba->dev, "Device power mode=%d, UIC link state=%d\n", @@ -1279,6 +1279,24 @@ out: return ret; } +static bool ufshcd_is_busy(struct request *req, void *priv, bool reserved) +{ + int *busy = priv; + + WARN_ON_ONCE(reserved); + (*busy)++; + return false; +} + +/* Whether or not any tag is in use by a request that is in progress. */ +static bool ufshcd_any_tag_in_use(struct ufs_hba *hba) +{ + struct request_queue *q = hba->cmd_queue; + int busy = 0; + + blk_mq_tagset_busy_iter(q->tag_set, ufshcd_is_busy, &busy); + return busy; +} static int ufshcd_devfreq_get_dev_status(struct device *dev, struct devfreq_dev_status *stat) @@ -1633,7 +1651,7 @@ static void ufshcd_gate_work(struct work_struct *work) if (hba->clk_gating.active_reqs || hba->ufshcd_state != UFSHCD_STATE_OPERATIONAL - || hba->lrb_in_use || hba->outstanding_tasks + || ufshcd_any_tag_in_use(hba) || hba->outstanding_tasks || hba->active_uic_cmd || hba->uic_async_done) goto rel_lock; @@ -1687,7 +1705,7 @@ static void __ufshcd_release(struct ufs_hba *hba) if (hba->clk_gating.active_reqs || hba->clk_gating.is_suspended || hba->ufshcd_state != UFSHCD_STATE_OPERATIONAL - || hba->lrb_in_use || hba->outstanding_tasks + || ufshcd_any_tag_in_use(hba) || hba->outstanding_tasks || hba->active_uic_cmd || hba->uic_async_done || ufshcd_eh_in_progress(hba)) return; @@ -2457,22 +2475,9 @@ static int ufshcd_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *cmd) hba->req_abort_count = 0; - /* acquire the tag to make sure device cmds don't use it */ - if (test_and_set_bit_lock(tag, &hba->lrb_in_use)) { - /* - * Dev manage command in progress, requeue the command. - * Requeuing the command helps in cases where the request *may* - * find different tag instead of waiting for dev manage command - * completion. - */ - err = SCSI_MLQUEUE_HOST_BUSY; - goto out; - } - err = ufshcd_hold(hba, true); if (err) { err = SCSI_MLQUEUE_HOST_BUSY; - clear_bit_unlock(tag, &hba->lrb_in_use); goto out; } WARN_ON(hba->clk_gating.state != CLKS_ON); @@ -2494,7 +2499,6 @@ static int ufshcd_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *cmd) if (err) { ufshcd_release(hba); lrbp->cmd = NULL; - clear_bit_unlock(tag, &hba->lrb_in_use); goto out; } /* Make sure descriptors are ready before ringing the doorbell */ @@ -2641,44 +2645,6 @@ static int ufshcd_wait_for_dev_cmd(struct ufs_hba *hba, return err; } -/** - * ufshcd_get_dev_cmd_tag - Get device management command tag - * @hba: per-adapter instance - * @tag_out: pointer to variable with available slot value - * - * Get a free slot and lock it until device management command - * completes. - * - * Returns false if free slot is unavailable for locking, else - * return true with tag value in @tag. - */ -static bool ufshcd_get_dev_cmd_tag(struct ufs_hba *hba, int *tag_out) -{ - int tag; - bool ret = false; - unsigned long tmp; - - if (!tag_out) - goto out; - - do { - tmp = ~hba->lrb_in_use; - tag = find_last_bit(&tmp, hba->nutrs); - if (tag >= hba->nutrs) - goto out; - } while (test_and_set_bit_lock(tag, &hba->lrb_in_use)); - - *tag_out = tag; - ret = true; -out: - return ret; -} - -static inline void ufshcd_put_dev_cmd_tag(struct ufs_hba *hba, int tag) -{ - clear_bit_unlock(tag, &hba->lrb_in_use); -} - /** * ufshcd_exec_dev_cmd - API for sending device management requests * @hba: UFS hba @@ -2691,6 +2657,8 @@ static inline void ufshcd_put_dev_cmd_tag(struct ufs_hba *hba, int tag) static int ufshcd_exec_dev_cmd(struct ufs_hba *hba, enum dev_cmd_type cmd_type, int timeout) { + struct request_queue *q = hba->cmd_queue; + struct request *req; struct ufshcd_lrb *lrbp; int err; int tag; @@ -2704,7 +2672,11 @@ static int ufshcd_exec_dev_cmd(struct ufs_hba *hba, * Even though we use wait_event() which sleeps indefinitely, * the maximum wait time is bounded by SCSI request timeout. */ - wait_event(hba->dev_cmd.tag_wq, ufshcd_get_dev_cmd_tag(hba, &tag)); + req = blk_get_request(q, REQ_OP_DRV_OUT, 0); + if (IS_ERR(req)) + return PTR_ERR(req); + tag = req->tag; + WARN_ON_ONCE(!ufshcd_valid_tag(hba, tag)); init_completion(&wait); lrbp = &hba->lrb[tag]; @@ -2729,8 +2701,7 @@ static int ufshcd_exec_dev_cmd(struct ufs_hba *hba, err ? "query_complete_err" : "query_complete"); out_put_tag: - ufshcd_put_dev_cmd_tag(hba, tag); - wake_up(&hba->dev_cmd.tag_wq); + blk_put_request(req); up_read(&hba->clk_scaling_lock); return err; } @@ -4863,7 +4834,6 @@ static void __ufshcd_transfer_req_compl(struct ufs_hba *hba, cmd->result = result; /* Mark completed command as NULL in LRB */ lrbp->cmd = NULL; - clear_bit_unlock(index, &hba->lrb_in_use); /* Do not touch lrbp after scsi done */ cmd->scsi_done(cmd); __ufshcd_release(hba); @@ -4885,9 +4855,6 @@ static void __ufshcd_transfer_req_compl(struct ufs_hba *hba, hba->outstanding_reqs ^= completed_reqs; ufshcd_clk_scaling_update_busy(hba); - - /* we might have free'd some tags above */ - wake_up(&hba->dev_cmd.tag_wq); } /** @@ -5873,6 +5840,8 @@ static int ufshcd_issue_devman_upiu_cmd(struct ufs_hba *hba, int cmd_type, enum query_opcode desc_op) { + struct request_queue *q = hba->cmd_queue; + struct request *req; struct ufshcd_lrb *lrbp; int err = 0; int tag; @@ -5882,7 +5851,11 @@ static int ufshcd_issue_devman_upiu_cmd(struct ufs_hba *hba, down_read(&hba->clk_scaling_lock); - wait_event(hba->dev_cmd.tag_wq, ufshcd_get_dev_cmd_tag(hba, &tag)); + req = blk_get_request(q, REQ_OP_DRV_OUT, 0); + if (IS_ERR(req)) + return PTR_ERR(req); + tag = req->tag; + WARN_ON_ONCE(!ufshcd_valid_tag(hba, tag)); init_completion(&wait); lrbp = &hba->lrb[tag]; @@ -5956,8 +5929,7 @@ static int ufshcd_issue_devman_upiu_cmd(struct ufs_hba *hba, } } - ufshcd_put_dev_cmd_tag(hba, tag); - wake_up(&hba->dev_cmd.tag_wq); + blk_put_request(req); up_read(&hba->clk_scaling_lock); return err; } @@ -6250,9 +6222,6 @@ cleanup: hba->lrb[tag].cmd = NULL; spin_unlock_irqrestore(host->host_lock, flags); - clear_bit_unlock(tag, &hba->lrb_in_use); - wake_up(&hba->dev_cmd.tag_wq); - out: if (!err) { err = SUCCESS; @@ -8248,6 +8217,7 @@ void ufshcd_remove(struct ufs_hba *hba) { ufs_bsg_remove(hba); ufs_sysfs_remove_nodes(hba->dev); + blk_cleanup_queue(hba->cmd_queue); scsi_remove_host(hba->host); /* disable interrupts */ ufshcd_disable_intr(hba, hba->intr_mask); @@ -8411,9 +8381,6 @@ int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq) init_rwsem(&hba->clk_scaling_lock); - /* Initialize device management tag acquire wait queue */ - init_waitqueue_head(&hba->dev_cmd.tag_wq); - ufshcd_init_clk_gating(hba); ufshcd_init_clk_scaling(hba); @@ -8447,6 +8414,12 @@ int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq) goto exit_gating; } + hba->cmd_queue = blk_mq_init_queue(&hba->host->tag_set); + if (IS_ERR(hba->cmd_queue)) { + err = PTR_ERR(hba->cmd_queue); + goto out_remove_scsi_host; + } + /* Reset the attached device */ ufshcd_vops_device_reset(hba); @@ -8456,7 +8429,7 @@ int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq) dev_err(hba->dev, "Host controller enable failed\n"); ufshcd_print_host_regs(hba); ufshcd_print_host_state(hba); - goto out_remove_scsi_host; + goto free_cmd_queue; } /* @@ -8493,6 +8466,8 @@ int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq) return 0; +free_cmd_queue: + blk_cleanup_queue(hba->cmd_queue); out_remove_scsi_host: scsi_remove_host(hba->host); exit_gating: diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h index 4f1dec68a853..8fd6fd75cb5c 100644 --- a/drivers/scsi/ufs/ufshcd.h +++ b/drivers/scsi/ufs/ufshcd.h @@ -213,13 +213,11 @@ struct ufs_query { * @type: device management command type - Query, NOP OUT * @lock: lock to allow one command at a time * @complete: internal commands completion - * @tag_wq: wait queue until free command slot is available */ struct ufs_dev_cmd { enum dev_cmd_type type; struct mutex lock; struct completion *complete; - wait_queue_head_t tag_wq; struct ufs_query query; }; @@ -484,7 +482,7 @@ struct ufs_stats { * @host: Scsi_Host instance of the driver * @dev: device handle * @lrb: local reference block - * @lrb_in_use: lrb in use + * @cmd_queue: Used to allocate command tags from hba->host->tag_set. * @outstanding_tasks: Bits representing outstanding task requests * @outstanding_reqs: Bits representing outstanding transfer requests * @capabilities: UFS Controller Capabilities @@ -543,6 +541,7 @@ struct ufs_hba { struct Scsi_Host *host; struct device *dev; + struct request_queue *cmd_queue; /* * This field is to keep a reference to "scsi_device" corresponding to * "UFS device" W-LU. @@ -563,7 +562,6 @@ struct ufs_hba { u32 ahit; struct ufshcd_lrb *lrb; - unsigned long lrb_in_use; unsigned long outstanding_tasks; unsigned long outstanding_reqs; -- 2.30.2
